would my 06yz450 get the same miles pertank as the honda

ThumperKid250F

im just wondering if my 2006 yz450 would get the same miles pertank as a crf450 2006. reason im asking is because i sold my big tank last year when my bike blew up... my buddy on his honda can almost go a day riding on his stock tank so im wondering if i could make it as far as him?

grayracer513

But, it has a larger tank than the 1.8 gallons of the YZ450, and considerably higher gearing. From personal experience with a YZ and the standard tank, a 38 mile trip through the desert riding moderately will leave very little fuel in the tank.

DRX350

We aren't racing, we're just riding fast and hard. Like about a 6 out of 10 on effort. I know when I go into race mode (8/10 or more) I can run through 3 gallons in 70 miles. But I have a 350 too. The KTM has about a 60 mile range and the Honda has about a 50 mile+ range in go real fast mode.

grayracer513

So was I. On the 38 mile ride, I was taking it somewhat easy to stretch the tank. Neither the KTM nor your 350 have any particular relevance to the fuel consumption of the YZ450 for reasons already cited. It is what it is. It depends a great deal on how the bike is ridden, and varies quite a bit, but 20-23 is still reasonably accurate as a conservative estimate. If one cares to, he can always pack up two liters of fuel and a GPS or trip odo and see how far he can get. Just be sure to stay within range of the two liters after the first 40 miles.

DRX350

OK, here, a buddy I ride with has a 2002 YZ426 with mods and can get 50 miles to a tank and more if he conserves.

Quite frankly, unless you're racing, 20mpg on a 450 is absurd, you need to tune the carb. When I road raced a 650cc 4cyl (34mm carbs) I got about 20mpg and thats going full throttle for long periods of time most of which is acceleration (which uses more fuel). I also raced autocross which is nothing but acceleration, and my 1600cc engine used 3 gallons in a full day of heats.

Also you mentioned liters, are we talking Kms or miles/ Liters or gallons here? A good way is to put 1 gallon exactly and carry the spare fuel as you mentioned.

grayracer513

OK, here, a buddy I ride with has a 2002 YZ426 with mods and can get 50 miles to a tank and more if he conserves.

That fits. 40 miles on a stock 450 tank is realistic under those terms, and a 426 holds 20% more fuel. 50 miles from a 426 pencils out at 22.7 MPG.

Quite frankly, unless you're racing, 20mpg on a 450 is absurd, you need to tune the carb. When I road raced a 650cc 4cyl (34mm carbs) I got about 20mpg and thats going full throttle for long periods of time most of which is acceleration (which uses more fuel). I also raced autocross which is nothing but acceleration, and my 1600cc engine used 3 gallons in a full day of heats.

When you road raced a 650, you had vastly higher final gearing, as was the case when you autocrossed your car. The stock gearing in a YZ450 produces only 8.4 mph per 1000 RPM. So, when you're happily bouncing along at a comfy 45 mph across the open desert, the engine is spinning at just over 5300 RPM. Quite happily, of course, but that's more than 3600 power strokes per mile, and it still takes more fuel just to turn the engine that fast than it would if it were geared higher.

The 20-23mpg figure was, as I said, a safe number to count on, although you could do worse than that if your ride included a lot of dune climbs, etc. If one is planning on riding to some remote area, it's wise to err on the conservative side until you have established what your bike will do with you on it.

DRX350

That fits. 40 miles on a stock 450 tank is realistic under those terms, and a 426 holds 20% more fuel. 50 miles from a 426 pencils out at 22.7 MPG.

Don't forget to remember that his tank wasn't totally empty either.

When you road raced a 650, you had vastly higher final gearing, as was the case when you autocrossed your car. The stock gearing in a YZ450 produces only 8.4 mph per 1000 RPM. So, when you're happily bouncing along at a comfy 45 mph across the open desert, the engine is spinning at just over 5300 RPM. Quite happily, of course, but that's more than 3600 power strokes per mile, and it still takes more fuel just to turn the engine that fast than it would if it were geared higher.

Houston, we have a problem. That may be true if my 650 was a single, but it fires 2x per revolution and at 100mph-ish it revved 7500 so uhh, yeah 15,000 combustions per minute. Also the final Drive ratio was 3.38:1.

In autocross the highest average speed is about 30mph, AC is racing in a VERY tight course, my final drive ratio was actually 4.12:1, not a whole lot different than a bike. It too was a 4cyl; so at 4000RPM its firing 4 times as often as a dirt bike.

The 20-23mpg figure was, as I said, a safe number to count on, although you could do worse than that if your ride included a lot of dune climbs, etc. If one is planning on riding to some remote area, it's wise to err on the conservative side until you have established what your bike will do with you on it.

You are right on the fact that it is better to be safe than sorry, but, I think the best way to solve this is to run 'til empty on a full gallon and see.

ThumperKid250F

ok well thanks for your input guys:thumbsup: yea when we go out woods riding its like were racing the whole time. were going as fast as we can most of the time. so im guessing im going to have to get a bigger tank then.

grayracer513

A 4 cylinder 650 fires 4 times as often than a single, but each event is one quarter as large. 650 is 650, in one slice or 4. And in fact, a 4 cylinder is more efficient.

Your rear drive ratio may have been 4.12, but you were likely never in 4th gear, meaning that you have to figure in the reduction for second gear (for instance) which was probably something like 1.7:1. That gives you an overall final ratio of 7:1. The overall ratio of the YZ450 in 5th gear is 9.45:1 (rounding), 35% lower.

DRX350

ok well thanks for your input guys:thumbsup: yea when we go out woods riding its like were racing the whole time. were going as fast as we can most of the time. so im guessing im going to have to get a bigger tank then.

As a Big tanker too, I'd highly recommend using that foam for the inside. It really works well. That sloshing has thrown me askew more than once.

DRX350

A 4 cylinder 650 fires 4 times as often than a single, but each event is one quarter as large. 650 is 650, in one slice or 4. And in fact, a 4 cylinder is more efficient.

Your rear drive ratio may have been 4.12, but you were likely never in 4th gear, meaning that you have to figure in the reduction for second gear (for instance) which was probably something like 1.7:1. That gives you an overall final ratio of 7:1. The overall ratio of the YZ450 in 5th gear is 9.45:1 (rounding), 35% lower.

You like this huh!?

I'm tiring of this, a 4cyl uses more fuel than a single, sorry, no exceptions to the rule. Ford made a 1.8L V6 a while back that got 23mpg, what does a modern 4cyl 1.8 get; ~40? That's why most passenger cars have eliminated V8s, if a 4 or 6 can produce the same power, they will get better economy than a V8.

Also, on my autocrosser, each piston was 400cc, 87mm bore, It had 2-40mm two barrel carbs and there is no situation in which a dirt bike could use more fuel than a car regardless of gear ratios.

Look at the simple fact of mechanical resistance. A 450cc 4cyl has so many moving parts that it takes more energy (fuel) to keep them reciprocating.

DRX350

really i never really had a problem with the sloshing, in my yz 250 with the big tank, what foam are you talking about?

It's foam that you put inside the tank. IMS sells some, I forget the other brands, but I love it. Especially when the tank is about half full. You don't think there's sloshing occuring until you try the foam.

ThumperKid250F

It's foam that you put inside the tank. IMS sells some, I forget the other brands, but I love it. Especially when the tank is about half full. You don't think there's sloshing occuring until you try the foam.

As a side note; it comes out easy too.

cool im gunna have to look into it then. maybe ill give it a shot:thumbsup: